Jason Senteney is a 36-year-old corrections officer and volunteer firefighter from Torrington who says he wants to speak for the working class. Washington is out of touch with most Americans, Senteney says.

The 59-year-old Lummis was first elected in 2008 and easily won re-election in 2010 and 2012.

She says she has more work to do in protecting Wyoming's interests against federal overreach on issues like endangered species and water.

The winner could face a Democrat from Arizona who's unopposed in the primary.

The situation leaves open the possibility that a write-in candidate could win the Democratic nomination.